Odour controller

ABSTRACT

The present invention provides an odour controller comprising at least one absorbent mineral material and a microbiota that facilitates malodour-control. Preferably, the absorbent mineral material is expanded perlite and/or exfoliated vermiculite.

FIELD OF THE INVENTION

The present invention relates to an absorbent mineral material that hasbeen treated with microbiota that facilitates malodour-control. Inparticular, it relates to particles useful as animal litter and/oranimal bedding and having effective malodour-inhibiting properties.

BACKGROUND TO THE INVENTION

Clay has long been used as a liquid absorbent, and has found particularusefulness as an animal litter. However, clay has very poormalodour-controlling qualities, and in the process of using it, theinevitable build-up of waste leads to the production of severe malodour.There have been many attempts to produce animal litters that are bothabsorbent and malodour-controlling. One attempted solution to theproblem of odour control has been the introduction of granular activatedcarbon into the litter, such as that described in U.S. Pat. No.5,860,391 to Maxwell et al. Other means of reducing malodours includethe inclusion of baking soda and/or pleasantly odourised crystals in thelitter.

Other litters that provide some malodour control include biodegradablelitters made from various plant resources, including pine wood pellets,recycled newspaper, clumping sawdust, barley and dried orange peel.

Another class of materials used as litter is silica gel, often referredto as “crystal litter”. This is a porous granular form of sodiumsilicate. It has the highest absorbency of all currently used littersand has excellent moisture control, as well as providing good malodourelimination for an extended period of time compared to other litters.

The human objection to malodour is not the only reason why it isdesirable to reduce it. Studies have shown that cats prefer to uselitter having little or no smell. One theory is that cats like to marktheir territory by urinating in it. If cats return to their litterboxand they cannot sense their own odour, they will try to mark theirterritory again. The nett effect of this is that cats return to use thelitter box more often if the odour of their markings is reduced. Thatis, the length of time before the litter needs changing can be increasedif the malodour can be reduced. What is needed is an absorbent materialhaving improved malodour-controlling properties, and one that maintainssuch properties for longer periods of time.

SUMMARY OF THE INVENTION

The present invention provides an odour-controller comprising at leastone absorbent mineral material and a microbiota which facilitatesmalodour-control. Preferably, the absorbent mineral material is expandedperlite, exfoliated vermiculite, or a mixture thereof, and themicrobiota comprises a probiotic formulation. Preferably, the probioticformulation comprises: i) non-pathogenic, heterotrophic microorganisms;and/or non-pathogenic, autotrophic microorganisms. More preferably, themicroorganisms are non-genetically modified microorganisms.

The present invention also provides a method for producing anodour-controller, the method including the steps of: i) heating anindustrial mineral to produce an absorbent mineral material; and thenii) applying a microbiota which facilitates malodour-control to theabsorbent mineral material, whereby the absorbent mineral material incombination with the microbiota comprise the odour-controller.Preferably, the industrial mineral material is perlite, vermiculite or amixture thereof, whereby the absorbent mineral material is expandedperlite and/or exfoliated vermiculite, respectively. Preferably, theprobiotic formulation comprises non-pathogenic, heterotrophicmicroorganisms. More preferably, the microorganisms are non-geneticallymodified microorganisms.

The odour-controller of the present invention may find particular use asan animal litter, as discussed in detail below. Accordingly, the presentinvention provides an odour-control animal litter. The odour controllermay also be used in other applications, such as bedding for smallanimals or in refuse containers or garbage bins.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the number of viable bacteria for different probiotics andapplications, as explained in the Examples.

DETAILED DESCRIPTION OF THE INVENTION

The following description refers to specific embodiments of the presentinvention and is in no way intended to limit the scope of the presentinvention to those specific embodiments.

In one preferred form of the present invention, the odour controller inemployed as an animal litter which finds use as a litter for a largenumber of different domestic and/or commercially relevant animalsincluding, but not limited to, cats, dogs, rabbits, ferrets and guineapigs. The following description is therefore directed primarily to thisapplication and it is to be understood that the term “litter”, as usedthroughout, is a reference to the material that is generally used forsuch animals to urinate and/or defecate onto or into. It is also to beunderstood that animal litter may also be used in bedding areas for manyanimals as, for example, an absorbent material onto which animals eitherurinate or defecate.

The absorbent mineral material upon which the present invention is basedis preferably selected from expanded perlite and/or exfoliatedvermiculite. Perlite is an industrial mineral and is a generic term usedto describe naturally occurring siliceous rock. A distinguishingfeature, which sets perlite apart from other volcanic, glasses, is thatwhen heated to a suitable point in its softening range, it expands fromabout four to about twenty times its original volume. This expansion isdue to the presence of two to six percent water (by weight) in the crudeperlite ore which, when quickly heated to above 800° C., vaporizes. Thiscauses the perlite ore to pop in a manner similar to popcorn whichresults in the creation of a matrix of pores in the expanded perlite.

Expanded perlite is typically characterised by its porous-like particlestructure, having voids therein which may be filled with liquid or waterif such is made available to the particle. The retention capacity ofexpanded perlite varies depending on particle size. Generally, however,perlite can hold approximately 300-400% of its own weight in moisture orliquids, which is very similar to vermiculite particles.

Expanded perlite is typically graded according to its specific particlesize. For example: Superfine material has a size of 0.5-2.0 mm; Finematerial has a size of 1.0-3.0 mm; Medium material has a size of 2.0-4.0mm; Coarse material has a size of 3.0-6.0 mm; and Super Coarse materialhas a size of 6.0-12.0 mm. Finer grades of perlite can also bemanufactured such as: 0.20-0.40 mm, 0.40-0.60 mm; and 0.60-0.80 mm.However, in order to achieve such particle size control, the perlite oremust either be crushed prior to expansion or the expanded perlite mustbe crushed post-expansion. It is to be understood that all grades and/orsizes of perlite are equally encompassed by the present disclosure.

Vermiculite is also an industrial mineral and is a naturally occurringmaterial. It has a typical chemical formula of: (Mg, Ca, K,Fe^(II))₃(Si, Al, Fe^(III))₄O₁₀(OH)₂•4H₂O. Table 1 below shows a typicalchemical analysis of vermiculite and perlite, respectively.

TABLE 1 Chemical Analysis of Vermiculite and Perlite (wt %) ComponentVermiculite Perlite Silica (SiO₂) 38-46%  70-75% Alumina (Al₂O₃) 10-16% 12-15% Potash (K₂O)  1-6%    3-5% Iron Oxide (Fe₂O₃)  6-13%  0.5-2%Lime (CaO)  1-5% 0.5-1.5% Magnesia (MgO) 16-35% 0.2-0.7% Titania (TiO₂) 1-3% — Water (H₂O)  8-16%    2-6%

Vermiculite is characterised by having layers of silicate latticestructures in which the silicate layer units have a thickness ofapproximately 1 nm. As noted above, the main elements present in thelayers are magnesium, aluminium, silicon and oxygen. The layers areseparated by one or two sheets of water molecules associated withcations, such as magnesium, calcium, sodium and hydrogen, the layersbeing of considerable lateral extent relative to their thickness of 1nm.

Vermiculite is another industrial mineral that expands when heated, theexpansion process being termed exfoliation. Typically, the vermiculiteore is heated to a temperature of 600-750° C., at which point, watertrapped between the layers vaporizes thereby causing the ore to expandor “exfoliate”. Since the ore is substantially horizontally arranged orlayered, exfoliation results in elongated vermiculite, which resemblesworms. The resultant exfoliated vermiculite is porous due to theseparation of the layers during exfoliation.

Exfoliated vermiculite is frequently graded according to its particlesize. For example, Grade 1 material has a size of 0-1 mm, Grade 2material has a size of 2-5 mm,

Grade 3 material has a size of 3-8 mm, and Grade 4 material has a sizeof 6-18 mm. The Grade 4 material is the largest and generally hasliquid-holding capacity, of approximately 400% by volume. It is to beunderstood that all grades and/or sizes of vermiculite are equallyencompassed by the present disclosure.

Animal litters typically include absorbent materials, for example, clayssuch as bentonite and calcined clays, which are safe and non-irritatingto the animals. Clays generally absorb relatively substantial amounts ofliquids. Other litter-suitable, porous, absorbent materials, that may beused alone or in combination, include straw, sawdust, wood chips, woodshavings, porous polymeric beads, shredded paper, bark, cloth, groundcorn husks, cellulose, water-insoluble inorganic salts, such as calciumsulphate, and sand. All of the above-mentioned absorbent materials arecapable of absorbing and retaining liquid within their porous matrices,or, in the case of sand, absorbing liquid onto its surface. It is withinthe scope of the present invention to include additional absorbentmaterials such as those described above in order to provide additionalabsorptive properties to the animal litter of the present invention.Accordingly, it is to be understood that an animal litter of the presentinvention is to be predominantly composed of exfoliated vermiculiteand/or expanded perlite, but may include additional absorbent materialssuch as those described above.

It is the porosity of exfoliated vermiculite and expanded perlite whichmakes these materials suitable to use as animal litter, since anyapplied liquid will be absorbed into the pores and voids of the solidmaterial. For example, exfoliated vermiculite includes voids between thelayers thereof which can accommodate liquid. While the followingdiscussion refers predominantly to vermiculite, it applies equally toperlite.

In some embodiments of the present invention, the absorbent mineralmaterial may be formed into agglomerates or pellets. Formation intopellets may involve the use of pressure and/or an adhesive. The natureof the absorbent mineral material is such that the application of onlymoderate pressure is required before the material begins to collapse andlose its ability to absorb liquid. It is therefore envisaged that anadhesive, such as a glue or a starch, may be used. Exemplary adhesivesinclude, but are not limited to, bentonite, lime, gum arabic andcarrageenan. The skilled person will appreciate that the main functionof the adhesive is simply to adhere a small number of particles togetherto form agglomerates or pellets. In some embodiments of the presentinvention, the particles of the absorbent mineral material may beadhered together by using a starch. In a typical embodiment, a foodstarch may be used. Starch is a carbohydrate consisting of a largenumber of glucose units joined by glycosidic bonds such as in linear andhelical amylose and in branched amylopectin.

Pelletising of the absorbent mineral material is typically carried outafter expansion/exfoliation by mixing and/or agitating together theabsorbent mineral material with an adhesive solution and drying theresultant pellets/agglomerates. In addition, further litter materialsmay by combined with the absorbent mineral material during the mixingwith the adhesive solution. These further litter materials may includeclay or sawdust, or any other absorbent material that is typically foundin animal litters. In some embodiments of the present invention, thepellets may be formed by extruding or agglomerating the absorbentmaterial(s) and adhesive solution mixture.

In yet further embodiments of the present invention, the odourcontroller, in the form of an odour-control animal litter may furtherinclude a clumping agent whereby, upon wetting, the absorbent mineralmaterial, or pellets thereof, clump together to facilitate their removalfrom a litter tray. The skilled person will be aware of the use of suchagents in currently available animal litters and can identify suitableagents for use with the vermiculite/perlite based odour control animallitter of the present invention.

While absorption of liquid makes the litter more pleasant for the animalto use, it does not necessarily significantly reduce or eradicatemalodours emanating from the litter. Accordingly, the present inventionalso provides an odour-control animal litter comprising, at least oneabsorbent mineral material that has been further treated withmicrobiota. As noted above, the absorbent mineral material is preferablyselected from expanded perlite and exfoliated vermiculite. In someembodiments, the absorbent mineral material may comprise one or both ofexpanded perlite and exfoliated vermiculite. Most preferably, theabsorbent material is exfoliated vermiculite. Preferably, the microbiotaused to treat the absorbent mineral material is a probiotic formulation.In particular, the Applicant has found that the use of a sufficientamount of a probiotic formulation in combination with an absorbentmineral material provides effective malodour control.

The microbiota of the litter of the present invention includesindustrial microorganisms. The term “microbiota”, as used herein,includes all microorganisms added to the lifter. In preferredembodiments, the microbiota includes “probiotic” microorganisms. Theterm “probiotic” is typically used in relation to “beneficial”microorganisms that are used as dietary supplements for humans. Suchprobiotic organisms are generally used to modify the intestinal flora ofthe user and are essentially a culture of live and/or dormant bacteriaand/or yeast. The term “dormant” in relation to microorganisms includes,but is not limited to, spores that are activated upon exposure toappropriate conditions. The present invention uses probiotic organismsto reduce malodours associated with animal litter that has been soiledby urine and/or faeces. Accordingly, as used herein, the term “probioticorganisms” is simply used to refer to non-harmful and/or beneficialmicroorganisms, such as, but not limited to bacteria and/or yeasts.Further, a “probiotic formulation” of the present invention is aformulation comprising one or more probiotic organisms.

The use of bacteria and/or yeast to reduce malodours iscounter-intuitive to conventional thinking since it is bacteria (andother microorganisms) that are generally responsible for many of themalodours associated with urine and faeces. However, the Applicant hasadvantageously determined that a probiotic formulation is able to imparta malodour-inhibiting property to the absorbent material used as animallitter. Without being bound by theory, it is believed that the probioticorganisms: i) capture and degrade malodour-causing compounds before theycause excessive malodour; and/or degrade the substrates upon whichmalodour-causing bacteria would normally grow.

Malodours are typically caused by the presence of high levels of variouscompounds, including, but not limited to: ammonia-containing andsulphur-containing compounds and gases, including, but not limited to3-mercapto-3-methylbutan-1-ol and hydrogen sulphide. These compounds maybe broken down by the probiotic organisms.

This process changes the underlying microbial ecology of the treatedarea to being one that is balanced, healthy and one which controls there-emergence of malodours as well as the re-emergence ofmalodour-causing bacteria.

Preferably, the probiotic formulation comprises non-pathogenic,heterotrophic microorganisms. Non-pathogenic organisms do not causedisease and are of minimal potential hazard to the environment. Thespecies used are preferably isolates of naturally occurring organismsand are not genetically engineered or modified. Heterotrophs areorganisms that require organic compounds as their carbon/nutrientsource. The preferred species are those that use the carbon sources inpet. urine and faeces for growth. Organisms in the probiotic formulationmay be active cells or cells in an inactive/dormant form. Autotrophicorganisms may also be applied which use inorganic substrates, such asammonia, for energy.

In certain embodiments, the probiotic formulations may comprise yeasts,Actinobacteria, Firmicutes and Gram negative bacteria. The preferredyeast is the common budding yeast, Saccharomyces cerevisiae. This yeast,under the name S. boulardii has been used previously as a probiotic totreat diarrhoea caused by bacteria. S. cerevisiae has also been shown tosurvive in the gastrointestinal tract while eliminating the potentiallypathogenic bacteria residing therein; however, it does not colonize thegastrointestinal tract.

Preferred species of Firmicutes include Bacillus and Lactobacillusspecies. Lactobacillus casei is among the best-documented probiotics andhas been extensively studied. This bacterium finds many applications inthe food and diary industries. In addition, L. casei has been combinedwith other probiotic strains of bacteria in randomized trials to studyits effects in preventing antibiotic associated diarrhoea andClostridium difficile infections. Other preferred species of Firmicutesinclude B. subtilis, B. coagulans B. cereus and L. plantarum includingspores of those species that produce spores.

Preferred Proteobacteria include Rhodopseudomonas palustris; which is aGram negative, photosynthetic, non-sulphur purple bacteria. Like anumber of other probiotic organisms, it is metabolically versatile byvirtue of its ability to grow under both aerobic and anaerobicconditions. In the presence of oxygen, R. palustris generates energy bydegrading a variety of carbon-containing compounds including sugars,lignin monomers, polymers and methanol. Another preferred Proteobacteriais Rhodobacter sphaeroides.

Preferred Actinobacteria come from the genus Streptomyces. Preferredspecies include, but are not limited to, S. albus and S. griseus. Thesebacteria may produce an antibiotic compound that may help to prevent thegrowth of malodour-causing bacteria.

In further embodiments, the probiotic formulation may comprise yeast,Actinobacteria, Firmicutes, Proteobacteria and Chloroflexi. Genera thatare useful in the present invention include, but are not limited to:Bacillus Bifidobacterium, Lactobacillus, Lactococcus, Proteus,Pseudomonas, Rhodobacter, Rhodopseudomonas, Sacchromyces, Streptococcusand Streptomyces.

The probiotic formulations for use in the present invention may includeany one or more type or species of microorganism, including, but notlimited to, spores from more than one species of Bacillus.

In addition to microorganisms, purified enzymes may be included in theanimal litter of the present invention. In certain embodiments of thepresent invention, the enzymes may be included in the probioticformulation. Enzymes are substrate-specific and fast-acting. Inenzymatic reactions, the malodourous compounds are converted intonon-odourous compounds. Examples of potentially beneficial enzymesinclude uricases, ureases and proteases.

Metal ions may also be included in the animal litter of the presentinvention, to inhibit odour formation. For example, gold, silver and/orcopper ions may be added, these can bind to and neutralise pheromones,such as felinine, which generate malodours. Again, these metal ions maybe included in the probiotic formulation to simplify its incorporationinto the animal litter.

In certain embodiments of the present invention, a surfactant/wettingagent may be included in the probiotic formulation. Thesurfactant/wetting agent may be used to assist the application processand the adherence of microbes to the absorbent mineral material.Possible agents include, but are not limited to, sodium xylenesulfonateor sodium lauryl ether sulphate.

The probiotic formulation for use in the present invention is typicallyprepared as a liquid formulation with an aqueous basis. The liquidcarrier for the probiotics may include any one or more of the componentsmentioned above together with a buffer to keep the microorganisms underconditions whereby they remain viable. Typically, the liquid carrierwill be buffered to approximately pH 6. The liquid carrier may alsoinclude a carbon source for the microorganisms once they begin to growor come out of dormancy. In one embodiment, it is envisaged thatmolasses may be used as the carbon source.

Application of the probiotic formulation to the at least one absorbentmineral material may be done by any method known in the art. Typically,application will be achieved by a spray methodology. The spray mayinclude a dried probiotic formulation such as a powder, or a wetprobiotic formulation such as a mist. In both cases, it is preferable toallow the absorbent mineral material to cool slightly after beingprocessed at high temperature, to prevent damage to the microbialorganisms. It is however, preferable to apply the probiotic formulationas soon as practicable after the absorbent mineral material has beenprocessed since, for example, perlite and vermiculite expandconsiderably during their exfoliation/expansion but then relax andshrink slightly as they cool. In order to allow best access to the manypores and/or voids present in the absorbent mineral material, it istherefore preferable to apply the probiotic formulation while theabsorbent mineral material is in its most expanded state.

The probiotic formulation may be added to the vermiculite, perlite, ormixture thereof, after the screening phase, but before the product isbagged. Preferably, the probiotic formulation is sprayed onto thevermiculite/perlite. The treated vermiculite/perlite is then availableto be bagged before sale. Typically, the treated vermiculite/perliteanimal litter is prepared in bag sizes of 8L, 18L, 27L and 40L.

As noted above, it is envisaged that the odour control animal litter ofthe present invention may be formed as pellets and/or agglomerates.Treatment of the pellets and/or agglomerates with the probioticformulation may be carried out at any time, either before, during orafter pellet/agglomerate formation. In the case of treatment duringpellet/agglomerate formation, the probiotic formulation may be combinedwith the adhesive solution or may be added separately to the mixture.

In some embodiments of the present invention, a malodour-masking agentmay also be added to the litter. Masking agents may include fragrancesthat are pleasant to humans. It should be noted that some fragrances,even at low concentrations, might discourage animals from using thetreated litter. Accordingly, the concentration and identity of anymasking agent must be carefully selected.

Yet another difficulty associated with current animal litters is thedisposal thereof. Many users are loath to subject their gardens orlandfill sites to the application of soiled animal litter for a numberof reasons, including its malodour. The animal litter of the presentinvention may be used as a carrier of fertilizer or may be simply mixedwith soil as a conditioning agent. The mineral material that is thebasis of the litter is a naturally occurring product that can be used tointroduce air into the soil as well as provide reservoirs for waterstorage. The animal urine and/or faeces in soiled litter may function asa fertilizer through the synergistic actions of the probiotic organismswith soil organisms. This application of the soiled litter is applicableto domestic gardens as well as to landfill sites where the soiled littercan also produce similar beneficial effects.

The odour-controller of the present invention may also be used in, oras, bedding material for small animals and pets, such as, but notlimited to: guinea pigs, mice, rats, reptiles, and birds.

One of ordinary skill in the art will appreciate that materials andmethods, other than those specifically exemplified can be employed inthe practice of the invention without resort to undue experimentation.All art-known functional equivalents, of any such materials and methodsare intended to be included in this invention. The terms and expressionswhich have been employed are used as terms of description and not oflimitation, and there is no intention that in the use of such terms andexpressions of excluding any equivalents of the features shown anddescribed or portions thereof, but it is recognized that variousmodifications are possible within the scope of the invention claimed.Thus, it should be understood that although the present invention hasbeen specifically disclosed by examples, preferred embodiments andoptional features, modification and variation of the concepts hereindisclosed may be resorted to by those skilled in the art, and that suchmodifications and variations are considered to be within the scope ofthis invention as defined by the appended claims.

The present invention is not to be limited in scope by the specificembodiments and Examples described herein, which are intended as singleillustrations of individual aspects of the invention, and functionallyequivalent methods and components are within the scope of the invention.Indeed, various modifications of the invention, in addition to thoseshown and described herein will become apparent to those skilled in theart from the foregoing description and accompanying Example. Suchmodifications are intended to fall within the scope of the presentinvention. Indeed, the use of the odour controller to line refusecontainers used by households to dispose of household rubbish or inrubbish bins used in public places, is also contemplated as fallingwithin the scope of the present invention.

EXAMPLE Preparation of Probiotic-Treated Vermiculite and/or PerliteVermiculite

Vermiculite ore was graded prior to its use. In this exemplaryembodiment, Grade 4/Large Grade vermiculite ore was used. The ore wasexfoliated using standard procedures. For example, the ore was loadedinto a furnace via a conveyor; it then travelled through the furnace byvacuum and gravity. The ore was heated to a temperature of 500-750° C.,at which point, water trapped in each ore-particle evaporated and causedthe particle to “exfoliate”. The exfoliated vermiculite was thenscreened to remove any additional small particles that were notpreviously removed from the ore.

Perlite

Perlite ore was graded prior to its use. In this exemplary embodiment,Coarse perlite ore was used. The ore was expanded using standardprocedures. For example, after the ore was loaded into a furnace via aconveyor, it then travelled through the furnace by vacuum and gravity.The ore was heated to a temperature of 800-1100° C., at which point,water trapped in each ore-particle evaporated and caused the particle to“expand”. The expanded perlite was then screened to remove anyadditional small particles that were not previously removed from theore.

Probiotic

Many of the probiotics currently available claim to reduce malodoursassociated with, inter alia, pet urine. Twelve probiotics were reviewedand one product (X) stood out for its scientific basis, extendedshelf-life, proven record and absence of fragrance. Trials had begunwith another product (Y), and it together with product X were selectedas the subjects for further investigations. The probiotics were appliedat different concentrations and at various stages of vermiculitemanufacturing to ensure that the application procedure is efficient andeffective. The effectiveness has been determined by establishing totalnumbers of active bacteria for each probiotic and its applicationprocess (FIG. 1). Product X has higher numbers of viable cells and ithas been confirmed that the active ingredients of product X (Bacillusspores) are not activated (germinated) during application in a hotfurnace (˜60° C.). It was shown that transporting and storing the petlitter for an extended period of time had no adverse effect. Aftertransportation and three months storage, the probiotic was still foundto be effective. Further investigations are ongoing to determine theextended shelf-life of the probiotic after application to vermiculite.

The ability to control malodours will set this product apart from itscompetitors. To test product X against other probiotics and competitorpet litters (Z), trials have been conducted using a synthetic cat urinebased on the reference values for feline urine (Table 2).

TABLE 2 Composition of feline urine (%) Component % ammonia 0.05sulphate 0.18 phosphate 0.12 chloride 0.6 sodium 0.1 creatinine 0.1 uricacid 0.003 urea 2.0 water 95

The average adult cat uses its kitty litter tray 5 times per day,producing 20-44 mL/kg of urine and faeces per day. The average cat alsoweighs between 4 and 5 kilos. Therefore, 200 mL per day of theartificial urine was applied to a standard sized litter tray. The mostcommonly reported odour for pet litters is ammonia due to the breakdownof urea, which is closely associated with pH. While the pH remainedbelow approximately 7, very little ammonia was detectable. Therefore,products were assessed microbiologically using plate counts, microscopyand enzyme activity, and chemically for and Nitrogen values. It wasfound that after 14 days, the product X-treated vermiculite had a pH 1to 1.5 units lower than untreated vermiculite and a compressedpaper-style litter.

The application of product X to vermiculite was the most effectiveprobiotic. It was faster-acting with longer-lasting odour control thanproduct Y and competitor pet litter Z. The probiotic-treated vermiculiteeffectively controlled ammonia odours produced from the synthetic caturine for the duration of the trials (2 weeks) where others failed.

Product X is a commercially available, concentrated probioticformulation (Freshen™ Free, Novozymes A/S, Denmark). This formulation issold as a 10× concentrate and contains the following components at theindicated concentrations:

TABLE 3 Composition of Freshen ™ Free liquid carrier (%) Component %sodium xylene sulfonate 10-20 citric acid  5-10 alcohols, c12-14,ethoxylated 1-5 sodium nitrate 1-5 disodium laureth sulfosuccinate 1-5amine oxide 1-5 1,2-benzisothiazolin-3-one <0.55-chloro-2-methyl-4-isothiazolin-3-one/ <0.52-methyl4-isothiazolin-3-oneThe concentrated probiotic formulation further comprises a mixture ofseveral bacteria as mentioned above.

Where the terms “comprise”, comprises”, “comprising”, “include”,“includes”, “included” or “including” are used in this specification,they are to be interpreted as specifying the presence of the statedfeatures, integers, steps or components referred to, but not to precludethe presence or addition of one or more other feature, integer, step,component or group thereof.

Further, any prior art reference or statement provided in thespecification is not to be taken as an admission that such artconstitutes, or is to be understood as constituting, part of the commongeneral knowledge.

1. An odour controller comprising at least one absorbent mineralmaterial and a microbiota that facilitates malodour-control.
 2. Theodour controller of claim 1, wherein the absorbent mineral material isexpanded perlite and/or exfoliated vermiculite.
 3. The odour controllerof claim 1 or claim 2, wherein the microbiota comprises a probioticformulation.
 4. The odour controller of claim 3 comprising exfoliatedvermiculite treated with a probiotic formulation.
 5. The odourcontroller of claim 3 comprising expanded perlite treated with aprobiotic formulation.
 6. The odour controller of any one of claims 3 to5, wherein the probiotic formulation comprises non-pathogenic,heterotrophic microorganisms and/or non-pathogenic, autotrophicmicroorganisms.
 7. The odour controller of claim 6, wherein themicroorganisms are non-genetically modified microorganisms.
 8. Anodour-control animal litter comprising the odour controller of any oneof claims 1 to
 7. 9. A method for producing an odour controller, themethod including the steps of: i. heating an industrial mineral toproduce an absorbent mineral material; and ii. applying thereto amicrobiota that facilitates malodour-control to the absorbent mineralmaterial; whereby the absorbent mineral material and the microbiotacomprise the odour controller.
 10. The method of claim 9, furtherincluding the step of pelletising or agglomerating the industrialmineral material to form individual pellets or agglomerates.
 11. Themethod of claim 9 or 10, wherein the industrial mineral material isperlite, vermiculite or a mixture thereof.
 12. The method of any one ofclaims 9 to 11, wherein the microbiota comprises a probioticformulation.
 13. The method of claim 12, wherein the probioticformulation comprises non-pathogenic, heterotrophic microorganismsand/or non-pathogenic, autotrophic microorganisms.
 14. An odourcontroller produced according to the method of any one of claims 9 to13.
 15. The odour controller of claim 14, wherein the odour controlleris an odour-control animal litter comprising exfoliated vermiculitetreated with a probiotic formulation.